Heat exchanger and production method for the heat exchanger

ABSTRACT

A bracket portion and a caulking pawl portion are provided on a tank cap closing an end portion of a first refrigerant header tank of an evaporator. Brazing is carried out in a state where the pawl portion is caulked and provisionally fixed to side plates by the pawl portion. As the evaporator and a radiator for electric components are coupled through the bracket portion, the coupling distance can be reduced and a suitable fastening strength between the evaporator and the radiator for electric components can be secured.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a heat exchanger having a bracket and a production method for the heat exchanger. More particularly, the present invention is effective when applied to a composite-type heat exchanger, for a vehicle, having a plurality of heat exchangers integrated with one another.

2. Description of the Related Art

A heat exchanger having a bracket and a production method are disclosed in Japanese Patent Publication No. 3,591,569. According to this prior art technology, a core portion for executing heat exchange and side plates for reinforcing the core portion are provisionally fixed by a jig and, while the bracket is caulked and provisionally fixed in such a fashion as to protrude from the side plates, the bracket and the core portion are integrally coupled with each other by brazing.

This method eliminates a provisional fixing step for provisionally fixing the bracket to the side plates such as crewing and welding, and reduces the cost of production.

The necessity for a composite-type heat exchanger fabricated by integrating a plurality of heat exchangers with one another has been increasing in recent years. In hybrid vehicles, for example, a heat exchanger is necessary in which a heat exchanger operating as a condenser for a vehicle air conditioner and a heat exchanger operating as a radiator for cooling a driving electric motor are juxtaposed and integrated with each other with respect to an air flow.

When a composite-type heat exchanger is produced by preparing a plurality of heat exchangers according to the prior art and coupling the brackets of each heat exchanger with one another, the distance between the adjacent heat exchangers becomes large because each bracket is formed to protrude from a sheet-like side plate.

When the distance between the adjacent heat exchangers becomes large and the distance becomes large, the deflection amount of the bracket increases, owing to the vibration of the vehicle, and the fastening strength, between the adjacent heat exchangers, drops.

Therefore, to decrease the distance between the adjacent heat exchangers, the inventor of this invention has examined an arrangement in which the bracket is provided on a tank cap for closing an end portion of header tanks in which distribution and gathering of heat exchange fluids are done.

According to this constitution, the adjacent header tanks can be directly fastened by bolts through the bracket by arranging the bracket on the tank cap of one of the heat exchangers and disposing screw holes in the header tank of the other heat exchanger. The distance between the adjacent heat exchangers can then be reduced.

Nonetheless, it has been found out that when the tank cap on which the bracket is provided is caulked and provisionally fixed to the outer periphery of the header tank and is then brazed, the weight of the bracket adds to the tank cap to which the bracket is provided, so that the provisional fixing state cannot be kept when a brazing material is molten at the time of melting, and the tank cap falls off from the header tank.

This problem may be solved by employing a caulking/provisional fixing means that increases the caulking load, for provisionally fixing the tank cap having the bracket to the header tank, but the header tank is likely to undergo deformation. Provisional fixing means that uses screwing or welding is conceivable, too, but a process step for screwing or welding is necessary for provisional fixing and the production cost cannot be reduced.

SUMMARY OF THE INVENTION

In view of the problems described above, it is a first object of the present invention to couple a tank cap having a bracket provided thereon to a heat exchanger without inviting the increase in the production cost.

In a heat exchanger formed by integrating a plurality of heat exchangers, it is a second object of the invention to provide a heat exchanger capable of reducing the distance between adjacent heat exchangers and securing a fastening strength, and a production method thereof.

The present inventor has further examined simultaneous coupling of a tank cap and a bracket with a heat exchanger in a state where the tank cap and the bracket are provisionally fixed (sub-assembled) when the bracket is provided on the tank cap.

According to this method, the process step for conducting only coupling of the tank cap and the bracket can be eliminated and the bracket can be provided on the tank cap without inviting an increase in production cost.

However, when pawl portions, etc, for caulking and provisional fixing are provided on the bracket 24 for provisionally fixing the tank cap and the bracket, the shape of the bracket becomes more complicated and the strength of the bracket drops, during use, for reasons such as the concentration of the stress on a specific portion such as the pawl portion. When provisional fixing is made through screwing or welding, a production step that is more complicated than provisional fixing by caulking is necessary and the production cost increases.

In view of the problems described above, it is a third object of the invention to provisionally fix a tank cap to a bracket without inviting a drop in bracket strength and an increase in production cost.

It is a fourth object of the invention to provide a heat exchanger, formed by integrating a plurality of heat exchangers, capable of securing a fastening strength by using a bracket coupled to a tank cap, and a production method thereof.

In order to accomplish the above object, according to a first feature of the present invention, there is provided a heat exchanger comprising: a core portion (13) having a plurality of tubes (11) through which a fluid flows; side plates (21) arranged on both end sides of said core portion (13) and reinforcing said core portion (13); a pair of header tanks (14, 15) arranged on both end sides of said tubes (11) in a longitudinal direction and communicating with said tubes (11); and tank caps (23, 28) closing the ends of said header tank (14) in the longitudinal direction; wherein at least one of said tank caps (23, 28) is a tank cap (23) with a bracket having a bracket (23) provided thereon; said tank cap (23) with a bracket has provisional fixing means (21) to said side plates (21); and said tank cap (23) with a bracket is coupled with said header tank (14) in a state where it is provisionally fixed to said side plates (21) by said provisional fixing means (25 b).

According to the means described above, as a tank cap (23) with a bracket has provisional fixing means (25 b) to a side plate (21), the tank cap (23) with a bracket can be firmly coupled to the side plate (21) and can be bonded in such a state to a header tank (14).

As a result, the tank cap (23) having the bracket (26) provided thereon can be coupled to the heat exchanger without inviting an increase in production cost.

According to a second feature of the present invention, a heat exchanger comprising a first heat exchanger (1) and a second heat exchanger (2), wherein said first heat exchanger (1) includes: a first core portion (13) having a plurality of first tubes (11) through which a first fluid flows; side plates (21) arranged on both end sides of said first core portion (13) and reinforcing said first core portion (13); a pair of first header tanks (14, 15) arranged on both end sides of said first tubes (11) in a longitudinal direction and communicating with said first tubes (11); and tank caps (23, 28) closing the ends of said first header tank (14) in the longitudinal direction; wherein at least one of said tank caps (23, 28) is a tank cap (23) with a bracket having a bracket (26) provided thereon; and said second heat exchanger (2) includes: a second core portion (33) having a plurality of second tubes (31) through which a second fluid flows; and a pair of second header tanks (34, 35) arranged on both end sides of said second tubes (31) in a longitudinal direction and communicating with said second tubes (31); said tank cap (23) with a bracket having provisional fixing means (25 b) to said side plates (21); said bracket (23) with a bracket being coupled with said first header tank (14) in a state where it is provisionally fixed to said side plates (21); aid first heat exchanger (1) and said second heat exchanger (2) being coupled in parallel with each other through said bracket (26) with respect to a flow direction of a third fluid that executes heat exchange with said first fluid and said second fluid.

According to the means described above, the tank cap (23) having the bracket (26) provided thereon can be coupled to the first heat exchanger (1) without inviting an increase in production cost in the same way as the heat exchanger of the first feature described above.

As the first heat exchanger (1) and the second heat exchanger (2) are coupled through the bracket (24) coupled to the tank cap (23), the first header tank (14, 14) and the second header tank (34, 35) adjacent to each other can be fastened and the fastening strength can be secured by reducing the distance between the first heat exchanger (1) and the second heat exchanger (2).

In the heat exchangers having the first and second features, the provisional fixing means may concretely be a pawl portion (25 b) that is caulked to an outer edge portion of the side plate (21) when it is bent.

Accordingly, when the pawl portion (25 b) is caulked and provisionally fixed to the outer edge of the side plate (21), the tank cap (23) can be provisionally fixed easily and firmly. In other words, when the pawl portion (25 b) is bent in such a manner as to extend along the outer edge of the side plate (21), provisional fixing can be made in such a manner as to restrict the movement of the tank cap (23) in the axial direction of the header tank (14) and in the vertical direction of the core portion (13).

In the heat exchanger having the second feature, the provisional fixing means is a pawl portion (25 b) caulked to the outer edge of the side plate (21) when it is bent, and the pawl portion (25 b) may well be caulked to a portion in proximity with the coupling portion between the side plate (21) and the first header tank (14).

As will be explained in a later-appearing embodiment, deformation occurs in the side plate (21) after coupling owing to the heat at the time of coupling. This deformation amount is smaller at a portion in proximity with the coupling portion between the side plate (21) and the header tanks (14, 15) than the center side of the side plate (21).

Therefore, when the pawl portion (25 b) is caulked and provisionally fixed to the outer edge of the side plate (21) in proximity with the coupling portion between the side plate (21) and the header tank (14, 15), the tank cap (23) can be provisionally fixed easily and firmly and deviation of the fitting position of the tank cap (23), resulting from deformation of the side plate (21) after coupling, can be prevented.

Here, the term “in proximity with the coupling position” in the present invention means a range in which a quality defect in brazing does not occur owing to deviation of the fitting position of the tank cap (23) after coupling. For example, the range may be within 5 mm from the coupling position of the side plate (21) and the header tank (14).

The third feature of the present invention resides in a method for producing a first heat exchanger (1) of the heat exchanger having the second feature, which method comprises the first step for provisionally fixing a tank cap (23) with a bracket to a side plate (21) by provisional fixing means (25 b); and the second step for coupling the tank cap (23) with a bracket and a first header tank (14) after the first step.

According to this method, the first heat exchanger in the heat exchanger having the second feature can be produced.

According to a third feature of the present invention, a heat exchanger comprising: a core portion (13) having a plurality of tubes (11) through which a fluid flows; a pair of header tanks (14, 15) arranged on both end sides of said tubes (11) in a longitudinal direction and communicating with said tubes (11); and tank caps (23, 138) closing the ends of said header tanks (14, 15) in the longitudinal direction; a bracket (136) coupled with at least one of said tank caps (23, 138); and a pin member (137) for provisionally fixing said tank cap (23) and said bracket (136); wherein said pin member (137) is caulked and provisionally fixed to provisional fixing hole portion (134 b) formed in said tank cap (23) and a provisional fixing hole portion (136 c) formed in said bracket (136); and said tank cap (23) and said bracket (136) is coupled in a state where they are caulked and provisionally fixed.

According to the means described above, the tank cap (23) and the bracket (136) are provisionally fixed by caulking a pin member (137) to a pin provisional fixing hole portion (134 b) formed in the tank cap (23) and to a pin provisional fixing hole portion (136 c) formed in the bracket (136). Therefore, provisional fixing can be easily made without making the shape of the bracket (136) more complicated.

As a result, the tank cap (23) and the bracket (136) can be provisionally fixed without inviting a drop in the strength of the bracket (136) and an increase in the production cost.

According to a fourth feature of the present invention, a heat exchanger comprising a first heat exchanger (1) and a second heat exchanger (2), wherein said first heat exchanger (1) includes: a first core portion (13) having a plurality of first tubes (11) through which a first fluid flows; a pair of first header tanks (14, 15) arranged on both end sides of said first tubes (11) in a longitudinal direction and communicating with said first tubes (11); tank caps (23,138) closing the ends of said first header tanks (14, 15) in the longitudinal direction; a bracket (136) coupled with at least one of said tank caps (23, 138); and a pin member (137) for provisionally fixing said tank cap (23) and said bracket (136); and wherein said second heat exchanger (2) includes: a second core portion (33) having a plurality of second tubes (31) through which a second fluid flows; and a pair of second header tanks (34, 35) arranged on both end sides of said second tubes (31) in a longitudinal direction and communicating with said second tubes (31); said pin member (137) being caulked and provisionally fixed to a pin provisional fixing hole portion (34 b) formed in said tank cap (23) and to a pin provisional fixing hole portion (136 c) formed in said bracket (136); said tank cap (23) and said bracket (23) being coupled with each other in a state where they are caulked and provisionally fixed; said first heat exchanger (1) and said second heat exchanger (2) being coupled in parallel with each other through said bracket (136) with respect to a flow direction of a third fluid that executes heat exchange with said first fluid and said second fluid.

According to this method, as in the third feature of the heat exchanger, the tank cap (23) of the first heat exchanger (1) can be provisionally fixed to the bracket (136) without inviting a drop in the strength of the bracket (136) and an increase in production cost.

Because the first heat exchanger (1) and the second heat exchanger (2) are coupled with each other through the bracket (136) coupled to the tank cap (23), the first header tank (14, 15) and the second header tank (34, 35) adjacent to each other can be fastened and the fastening strength can be secured by reducing the distance between the first heat exchanger (1) and the second heat exchanger (2).

In the heat exchangers having the third and fourth features, the tank cap (23, 138) may contain a tank cap (138) to which the bracket (136) is not coupled.

Here, the tank cap (23) to which the bracket (136) is coupled may be the one that is obtained by disposing a pin provisional fixing hole portion (134 b) in the tank cap (138) to which the bracket (136) is not coupled.

According to this constitution, a mold used in the production process of the tank cap (138) on which the bracket (136) is not provided and a mold used in the production process of the tank cap (138) can be used in common and the production cost can be further reduced. Moreover, an assembly error can be prevented because it is easy to distinguish whether or not the bracket (136) is coupled depending on the existence/absence of the pin provisional fixing hole portion (134 b).

According to a fifth feature of the present invention, a production method of a heat exchanger, further comprises: the first step of caulking and provisionally fixing said pin member (137) to a pin provisional fixing hole portion (134 b) formed in said tank cap (23) and to a pin provisional fixing hole portion (136 c) formed in said bracket (136); and the second step of coupling said tank cap (23) and said bracket (136) under a state where they are caulked and provisionally fixed.

According to this method, the heat exchanger having the fourth feature can be produced.

Incidentally, the reference numerals in parentheses, to denote the above means, are intended to show the relationship of the specific means which will be described later in an embodiment of the invention.

The present invention may be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall structural view of a heat exchanger according to a first embodiment of the present invention;

FIG. 2 is a side view showing a fitting state of the heat exchanger of the first embodiment of the invention to a vehicle;

FIG. 3A is an overall front view of a tank cap of the first embodiment of the invention;

FIG. 3B is a right side view of FIG. 3A and is a top view of FIG. 3A;

FIG. 4 is a sectional view taken along a line B-B of the cap tank shown in FIG. 3A;

FIG. 5A is an overall front view of another tank cap according to the first embodiment of the invention;

FIG. 5B is a top view of FIG. 5A;

FIG. 6 is an enlarged view showing principal portions of the heat exchanger before provisional caulk-fixing;

FIG. 7 is an enlarged view showing the principal portions of the heat exchanger after provisional caulk-fixing;

FIG. 8 is a sectional view taken along a line D-D of the principal portions of the heat exchanger shown in FIG. 7;

FIG. 9 is an explanatory view useful for explaining deformation of the heat exchanger after brazing;

FIG. 10A is an overall front view of a tank cap of a second embodiment of the invention;

FIG. 10B is a top view of FIG. 3A;

FIG. 11A is an overall front view of a bracket of the second embodiment of the invention;

FIG. 11B is a top view of FIG. 11A;

FIG. 11C is a top view of FIG. 11A;

FIG. 12A is an overall front view of a tank cap and a bracket that are provisionally fixed according to the second embodiment of the invention;

FIG. 12B is a top view of FIG. 12A;

FIG. 13 is a sectional view taken along a line B′-B′ of FIG. 12A;

FIG. 14A is an overall front view of another tank cap of the second embodiment of the invention;

FIG. 14B is a top view of FIG. 14A;

FIG. 15 is an enlarged view showing principal portions of a heat exchanger in a provisional fixing state; and

FIG. 16 is a sectional view taken along a line H′-H′ of the principal portions of the hat exchanger shown in FIG. 15.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

To begin with, a first embodiment of the invention will be explained.

FIG. 1 is an overall front view of a heat exchanger for a hybrid vehicle according to an embodiment of the present invention. This heat exchanger is constituted by integrally combining a condenser 1 for radiating heat of a high-temperature, high-pressure refrigerant discharged from a compressor (not shown in the drawing) in a vehicle air conditioner and a radiator 2, for electrical components, for cooling electrical devices and components such as an electric motor, an inverter and a generator (all of which are not shown) for the hybrid vehicle.

Therefore, the condenser 1 is a first heat exchanger and the radiator 2 for the electric components is a second heat exchanger in this embodiment.

First, a vehicle mounting state of this heat exchanger will be explained. The heat exchanger is coupled with a radiator 3 for an engine as shown in FIG. 2 and is mounted to the vehicle rear side of a radiator grill 5 and a bumper reinforcing member 6 below a hood 4 as shown in FIG. 2.

The condenser 1 and the radiator 2 for the electric components are constituted on substantially the same plane and are juxtaposed with each other in an air flow direction (direction indicated by arrow A in FIG. 2) and the radiator 2 for the-electric components is positioned above the condenser 1.

The heat exchanger is arranged on the upstream side in the air flow direction with respect to the radiator 3 for the engine and is mounted in such a fashion that when the heat exchanger is viewed from the air flow direction, it overlaps with the radiator 3 for the engine. An electric fan 7 for supplying cooling air to the heat exchanger is arranged on the downstream side of the radiator 3 for the engine in the air flow direction.

Next, the condenser 1 and the radiator 2 for the electric components will be explained. Incidentally, the terms “up” and “down” and “front” and “rear” in the following explanation are based on the vehicle mounting condition shown in FIG. 2.

In the condenser 1, to begin with, a large number of refrigerant tubes 11 through which a refrigerant flows are stacked, and fins 12 for promoting heat exchange between the refrigerant and air are arranged between adjacent tubes 11. The refrigerant tubes 11 and the fins 12 constitute a substantially rectangular core portion 13.

A first refrigerant header tank 14 for distributing the refrigerant to the refrigerant tubes 11 and a second refrigerant header tank 15 for gathering the refrigerant from the refrigerant tubes 11 are arranged at both ends of the refrigerant tubes 11 in the longitudinal direction.

These first and second refrigerant header tanks 14 and 15 have the same number of slits (not shown) as the slits of the refrigerant tubes 11 and communicate with all the refrigerant tubes 11 through these slits.

A refrigerant inlet pipe 16 for allowing the refrigerant to flow into the condenser 1 and a refrigerant outlet pipe 17 for allowing the refrigerant to flow out from the condenser 1 are provided on the first refrigerant header tank 14. A gas/liquid separator 18 is arranged outside the second refrigerant header tank 15 (on the opposite side to the core portion 13). The gas/liquid separator 18 is a receiver that can separate a gas-phase refrigerant from a liquid-phase refrigerant and can store the liquid-phase refrigerant.

Incidentally, the second refrigerant header tank 15 and the gas/liquid separator 18 communicate with each other at two positions through a plate 19 having two through-holes 19 a and 19 b. The through-hole 19 a is arranged above the through-hole 19 b.

A first separator 14 a is arranged at a lower position inside the first refrigerant header tank 14 and a second separator 15 a is arranged at the same position as the first separator 14 a inside the second header tank 15. These first and second separators 14 a and 15 a divide the core portion 13 into two heat exchange portions.

The portion above the first and second separators 14 a and 15 a inside the core portion 13 is a condensation portion in which the gas-phase refrigerant flowing in from the refrigerant inlet pipe 16 is allowed to exchange heat with air and to condense the refrigerant. The refrigerant flowing out from the condensation portion 13 a passes through the through-holes 19 a of the plate 19 and flows into the gas/liquid separator 18.

Therefore, the refrigerant inlet pipe 16 is arranged above the first separator 14 a and the though-holes 19 are arranged above the second separator 15 a.

The portions below the first and second separators 14 a and 15 a in the core portion 13 are a super-cooling portion 13 b for allowing the liquid-phase refrigerant flowing in from the gas/liquid separator 18 through the through-holes 19 b to exchange heat with air and to super-cool the liquid-phase refrigerant. The refrigerant cooled in the super-cooling portion 13 b flows out from the refrigerant discharge port 17.

For this reason, the refrigerant outlet pipe 17 is arranged below the first separator 14 a and the through-hole 19 b is arranged below the second separator 15 a.

In this heat exchanger, the super-cooling portion 13 b is arranged below the condensation portion 13 a, the gas/liquid separator 18 is arranged on the side of the condensation portion 13 a and the super-cooling portion 13 b, and the upper part of the gas/liquid separator 18 protrudes upward from the upper end face of the condensation portion 13 a of the gas/liquid separator 18. A bracket 20 for coupling with the radiator 2 for the electric components is provided on the protruding portion from the upper end face of the condensation portion 13 a of the gas/liquid separator 18.

Side plates 21 that extend in parallel with the refrigerant tubes 11 and reinforce the core portion 13 are arranged at both ends of the refrigerant tubes 11 in the stacking direction. Two brackets 22 for mounting the heat exchanger according to this embodiment to the radiator for the engine are provided on the side plate 21 on the lower side in the stacking direction of the refrigerant tubes 11.

Tank caps for closing both ends of the respective header tanks are arranged at the upper end and the lower end of the first refrigerant header tank 14 and the second refrigerant header tank 15, respectively. First, the tank cap 23 provided on the upper end side of the first refrigerant header tank 14 will be explained with reference to FIGS. 3 and 4.

FIG. 3A is an overall front view of the tank cap 23, FIG. 3B is its right-hand side view and FIG. 3C is a top view. FIG. 4 is a sectional view taken along a line B-B of FIG. 3A. Incidentally, the tank cap 23 shown in FIGS. 3 and 4 represents the single body of the tank cap 23 before it is arranged at the upper end of the first refrigerant header tank 14.

First, the tank cap 23 includes a tank closing portion 24, a cap extension portion 25 and a bracket portion 26. Therefore, the tank cap 23 is a tank cap with a bracket in this embodiment.

The tank closing portion 24 and the cap extension portion 25 have substantially flat sheet-like shapes and are constituted integrally. The tank closing portion 24 closes the upper end of the first refrigerant header tank 14. The cap extension portion 25 extends from the tank closing portion 24 in such a manner as to overlap with the side plate 21 on the upper end side of the core portion 13, and is coupled with the side plate 21.

The tank closing portion 24 has a positioning flange 24 a for positioning the tank cap 23 and the first refrigerant header tank 14 and provisionally fixing them. The positioning flanges 24 a are disposed at three positions in such a manner that they can clamp the upper end portion of the first refrigerant header tank 14 from the outer peripheral side.

The cap extension portion 25 has a positioning flange 25 a for positioning and provisionally fixing the tank cap 23 and the side plate 21. The positioning flanges 25 a are disposed at two positions in such a manner that they can clamp the side plate 21 in the longitudinal direction. Furthermore, the cap extension portion 25 has pawl portions 25 b for caulking and provisionally fixing the side plate 21 from the longitudinal direction at two positions.

The bracket portion 26 is for coupling the condenser 1 to the radiator 2 for the electric components and has a coupling surface portion 26 a coupled with the tank closing portion 24 and a fitting surface portion 26 b to which the radiator for the electric components is fitted. The coupling surface portion 26 a and the fitting surface portion 26 b have a positional relation such that they cross each other substantially orthogonally on the front surface side of the condenser 1. The bracket portion 26 is substantially L-shaped as viewed from the side of the evaporator 1 as shown in FIG. 3B.

In this embodiment, the tank closing portion 24 has a through-hole 24 b for pin caulking and the bracket portion 26 has a through-hole 26 c for pin caulking as shown in FIG. 4. A pin 27 inserted into these through-holes 24 b and 26 c is applied with a load and caulked from the vertical direction to thereby couple the tank closing portion 24 and the bracket portion 26.

Though the tank closing portion 24 and the bracket portion 26 are caulked and coupled through the pin 27 in this embodiment, the tank closing portion 24 and the bracket portion 26 may be coupled by other means. Furthermore, the tank closing portion 24 and the bracket portion 26 may be integrally constituted by cutting work, for example.

Next, the tank caps 28 disposed at the lower end of the first refrigerant header tank 14 and the upper and lower ends of the second refrigerant header tank 15 will be explained with reference to FIG. 5. Each tank cap 28 only closes the end portion of the respective refrigerant header tank.

FIG. 5A is an overall front view of the tank cap 28 and FIG. 5B is its top view. The tank cap 28 includes a tank closing portion 28 a and a cap extension portion 28 b similar to those the tank cap 23 but does not have a bracket portion. Incidentally, the tank cap 28 in FIG. 5 represents the single body of the tank cap 28 before it is provided on the refrigerant header tank.

The tank closing portion 28 a has positioning flanges 28 c similar to the tank cap 23 at three positions but does not have a through-hole for pin caulking. Furthermore, the cap extension portion 28 b has positioning flanges 28 d similar to those of the tank cap 23 but does not have pawl portions for caulking and provisionally fixing to the side plate 21 from the longitudinal direction.

The condenser 1 has the constitution described above. In this embodiment, all the constituent components of the condenser 1 are formed of an aluminum alloy and are integrally coupled by brazing.

Here, the term “brazing” means a bonding technology using a brazing material or a solder without melting a base metal. Bonding at a melting point of higher than 450° C. by using a filler metal (brazing material), in particular, is referred to as “brazing” and coupling at a melting point of lower than 450° C. by using a filler metal (brazing material), in particular, is referred to as “soldering”. In this embodiment, “soldering” is used for integral coupling as will be later described.

Next, in the radiator 2 for the electric components, a large number of cooling water tubes 31, through which cooling water flows, are stacked and fins 32 for promoting the heat exchange between cooling water and air are arranged between adjacent cooling tubes 31. The cooling water tubes 31 and the fins 32 together constitute a substantially rectangular core portion 33.

A first cooling water header tank 34 for distributing cooling water to the cooling water tubes 31 and a second cooling header tank 15 for gathering cooling water from the cooling water tubes 3, each communicating with all the cooling water tubes 31, are arranged at both ends of the cooling tubes 31 in the longitudinal direction.

These first and second cooling water header tanks 34 and 35 have the same number of slits (not shown) as the slits of the cooling water tubes 31 and communicate with all the cooling water tubes 31 through these slits.

A cooling water inlet pipe 36 for allowing cooling water to flow into the radiator 2 for the electric components is disposed in the first cooling water header tank 34 and a cooling water outlet pipe 37 for allowing cooling water to flow out from inside the radiator 2 for the electric components and an air vent valve 38 are provided on the second cooling water header tank 35.

A screw hole (not shown) for coupling the condenser 1 with the radiator 2 for the electric components through the bracket portion 26 of the tank cap 23 of the condenser 1 is disposed below the first cooling water header tank 34. A screw hole (not shown) for coupling the condenser 1 with the radiator 2 for the electric components through the bracket 20 of the gas/liquid separator 18 of the condenser 1 is disposed below the second cooling water header tank 35.

Side plates 39 extending in parallel with the cooling water tubes 31 and reinforcing the core portion 33 are arranged at both ends of the cooling water tubes 31 in the stacking direction. Two fitting brackets 40 for fitting the radiator 2 for the electric components to the radiator 3 for the engine are arranged on the side plate 39 on the upper side of the cooling water tubes 31 in the stacking direction.

Tank caps (not shown) for closing both ends of the respective header tanks are arranged at the upper and lower ends of the first and second cooling water header tanks 34 and 35, respectively.

The radiator 2 for the electric components has the constitution described above. In this embodiment, all the constituent components of the radiator 2 for the electric components are formed of an aluminum alloy and are integrally coupled by brazing in the same way as the condenser 1. In this embodiment, the constituent components are integrally coupled by brazing as will be later described.

A bolt 41 penetrating through the bracket portion 26 of the tank cap 23 is fastened to the screw hole formed in the first cooling water header tank 34 and a bolt 42 penetrating through the bracket 20 of the gas/liquid separator 18 is further fastened to the screw hole formed in the second cooling water header tank 35 so that the condenser 1 and the radiator 2 for the electric components can be integrated with each other.

The heat exchanger having the constitution described above is mounted to the vehicle as shown in FIG. 2. When the electric fan 7 is operated and air is allowed to flow into the engine room from the radiator grill 5, the flowing air passes through the condenser 1 and the radiator 2 for the electric components.

In this instance, the condenser 1 causes the high-temperature/high-pressure refrigerant ejected from the compressor 1 to exchange heat with air to cool and condense the refrigerant. The radiator 2 for the electric components causes cooling water, the temperature of which rises after cooling the electric components, to exchange heat with the air and cools the cooling water.

Next, the production process of the heat exchanger according to the invention will be explained. The evaporator 1 and the radiator 2 for the electric components are separately produced and are then coupled integrally with each other as described above. Therefore, the production process of the evaporator 1 will be first explained.

In the production process of the evaporator 1, the condenser 1 is assembled by inserting a large number of refrigerant tubes 11 into the slit holes formed in the first and second refrigerant header tanks 14 and 15 and sandwiching the fins 12 between the refrigerant tubes 11.

The side plate 21 is arranged on the refrigerant tube 11 of the uppermost stage through the side plate 21 and the side plate 21 is also arranged below the refrigerant tube 11 of the lowermost stage through the fin 12. The side plates 21 are provisionally fixed by a wire 43 as shown in FIG. 9 lest they are deviated in the vertical direction. Incidentally, FIG. 9 explains deformation of the evaporator after brazing as will be later described and does not represent the provisional fixing state under this condition.

The refrigerant inlet pipe 16 and the refrigerant outlet pipe 17 are provisionally fixed to the first refrigerant header tank 14 by caulking at the through-hole positions formed in advance in the first refrigerant header tank 14. The first separator 14 a is provisionally fixed at a predetermined position inside the first refrigerant header tank 14.

On the other hand, the plate 19 and the gas/liquid separator 18 is provisionally fixed by caulking to the second refrigerant header tank 15 in such a fashion as to mate with the through-hole positions disposed in advance in the second refrigerant header tank 15.

Further, the bracket 22 for fitting the radiator 3 for the engine is provisionally fixed by caulking to the side plate 21 on the lower side.

In this state, all the components are held from both right and left sides by a dedicated jig lest they are deviated. The tank cap 23 is provisionally fixed to the upper end of the first refrigerant header tank 14 and the tank cap 28 is provisionally fixed to the lower end of the first refrigerant header tank 14 and to the upper and lower ends of the second refrigerant header tank 15.

More concretely, the upper end of the first refrigerant header tank 14 is clamped by the positioning flange 24 of the tank cap 23 and the side plate 21 is clamped and provisionally caulked for fixing by the positioning flange 25 a. The upper and lower ends of the header tanks 14 and 15 are clamped by the positioning flange 28 c of the tank cap 28 and the side plate 21 is clamped and provisionally caulked for fixing by the positioning flange 28 d.

The pawl potion 25 b of the tank cap 23 arranged at the upper edge of the first refrigerant header tank 14 is caulked to the side plate 21. FIGS. 6 and 7 show, enlarged, portions in proximity with the tank cap 23 (C portion in FIG. 1), whereby FIG. 6 shows the pawl portion 25 b before caulking and FIG. 7 shows the pawl portion 25 c after caulking. Dash line represents the radiator 2 for the electric components for reference. Furthermore, FIG. 8 is a sectional view taken along a line D-D in FIG. 7 and shows the state after the pawl portion 25 b is caulked.

As shown in FIG. 8, the pawl portion 25 b is bent in such a manner as to extend below the side plate 21 along the outer edge shape of the side plate 21 and is caulked. Consequently, the movement of the tank cap 23 in the axial direction of the header tank 14 and in the vertical direction of the core portion 13 can be restricted and provisional fixing by caulking stronger than provisional fixing by the positioning flanges 24 a and 25 a becomes possible.

Incidentally, the condenser 1 according to this embodiment is provisionally fixed by a wire 43. Each constituent component is provisionally fixed with a predetermined tension and each constituent component can keep the provisional fixing state even when it undergoes thermal expansion as it is heated during brazing.

Consequently, the amount of shrinkage becomes different when each constituent component is cooled after brazing and undergoes shrinkage. In other words, the amount of shrinkage is different between the portion that is restricted by the wire 43 and the portion that is not. For example, the portion of the evaporator 1 of this embodiment on the center side of the heat exchanger shrinks in such a manner as to be recessed in the directions F and G indicated by arrows. The dashed line in FIG. 9 represents the shape before deformation and the solid line represents the shape after deformation.

The amount of shrinkage becomes larger than the expansion amount at the portion restricted by the wire 43 owing to the restriction force of the wire 43. Therefore, when the tank cap 23 is provisionally fixed on the center side of the side plate 21, the positioning error of the tank cap 23 is more likely to occur with the deformation of the side plate 21 after brazing.

Therefore, the caulking position of the pawl portion 25 b is set to a position within 5 mm from the joint portion of the side plate 21 with the first refrigerant header tank 14 in this embodiment. In detail, the distance E shown in FIG. 7, that is, the distance from the joint portion of the side plate 21 with the first refrigerant header tank 14 to the center position of the pawl 25 b, may well be 5 mm or less.

In this state, all the constituent components are heated to about 600° C., by heating means, to melt the brazing material clad in advance to the surface of each constituent component. When cooling is done until the brazing material is solidified, the constituent components are integrally brazed and the evaporator 1 is produced.

Next, in the production process of the radiator 2 for the electric components, a large number of cooling water tubes 31 are fitted into the slit holes formed in the first cooling water header tank 34 and the second cooling water header tank 35 in the same way as in the production process of the condenser 1 and the fins 32 are sandwiched between the adjacent cooling water tubes 31 to assemble the radiator 2 for the electric components.

The side plate 39 is arranged on the cooling water tube 31 of the uppermost stage through the fins 32 and the side plate 39 is arranged below the cooling water tube 31 of the lowermost stage through the fins 32. These members are fixed by the wire lest they move in the vertical direction, in the same way as in the evaporator 1.

The cooling water inlet pipe 36 is provisionally fixed by caulking to the position of the communication hole that is formed in the first cooling water header tank 34, and the cooling water outlet pipe 37 and the air vent valve 38 are provisionally fixed by caulking to the position of the communication hole that is formed in the second cooling water header tank 35.

The bracket 22 for fitting to the engine radiator 3 is provisionally fixed by caulking to the side plate on the upper end side 39. In this state, the side plate 39 is fixed by the dedicated jig from both right and left sides lest it is deviated.

Next, the tank caps for the cooling water header tanks 34 and 35 are provisionally fixed to the upper and lower ends of the cooling water header tanks 34 and 35 in the same way as the condenser 1. Each constituent component is brazed in this state and the radiator 2 for the electric components is produced.

Next, the condenser 1 and the radiator 2 for the electric components that are separately produced as described above are coupled with each other by fastening the bolt 41 penetrating through the bracket portion 26 of the tank cap 23 to the screw hole formed in the first cooling water header tank 34 and the bolt 42 penetrating through the bracket 20 of the gas/liquid separator 18 to the screw hole formed in the second cooling water header tank 35. In this way the heat exchanger according to this embodiment is produced.

In the condenser 1 of the heat exchanger according to this embodiment, the pawl portion 25 b disposed on the tank cap 23 is strongly and provisionally fixed in such a manner as to encompass the outer peripheral side of the side plate 21 as described above. Therefore, the provisional fixing state of the tank cap 23 can be kept at the time of brazing without inviting an increase in production cost and the tank cap 23 can be bonded to the upper end of the first refrigerant header tank 14.

The pawl portion 25 b is provisionally fixed to the portion in proximity with the bond portion between the side plate 21 and the first refrigerant header tank 14 where the amount of deformation after brazing is small. Consequently, a positioning error of the tank cap 23 after brazing can be prevented. As a result, brazing quality defects such as the positioning error of the bracket portion 26 and liquid leakage from the bonding portion between the tank cap 23 and the first refrigerant header tank 14 can be effectively prevented.

Furthermore, the header tanks in proximity with the condenser 1 and the radiator 2 for the electric components are fastened to each other through the bracket portion 26 disposed on the tank caps 23. Consequently, it becomes possible to shorten the distance between the condenser 1 and the radiator 2 for the electric components and to secure the fastening strength.

Next, the second embodiment of the present invention will be explained.

FIG. 10A is an overall front view of the tank cap 23 and FIG. 10B is its top view. Incidentally, the tank cap 23 shown in FIGS. 10A and 10B represents the single body of the tank cap 23 before it is arranged on the upper end side of the first refrigerant header tank 14. The tank cap 23 closes the upper end portion of the first refrigerant header tank 14 and the bracket 136 for fitting is bonded to the tank cap 23.

The tank cap 23 includes a tank closing portion 134 and a cap extension portion 135. The tank closing portion 134 and the cap extension portion 135 are integrally constituted into a substantially flat sheet-like shape. The tank closing portion 134 closes the upper end of the first refrigerant header tank 14. The cap extension portion 135 extends from the tank closing portion 134 in such a manner as to overlap with the side plate 21 on the upper end side of the core portion 13, and is coupled to the side plate 21.

The tank closing portion 24 has a positioning flange 134 a for positioning the tank cap 23 and the first refrigerant header tank 14 and provisionally fixing them. The positioning flanges 134 a are disposed at three positions in such a manner that they can clamp the upper end portion of the first refrigerant header tank 14 from the outer peripheral side. A pin provisional fixing hole portion 134 b, as a through-hole to which a later-appearing pin member 137 is caulked, is formed at a substantial center of the tank closing portion 134.

The cap extension portion 135 has a positioning flange 135 a for positioning and provisionally fixing the tank cap 23 and the side plate 21. The positioning flanges 135 a are disposed at two positions in such a manner that they can clamp the side plate 21 from the longitudinal direction. Furthermore, the cap extension portion 135 has pawl portions 135 b for caulking and provisionally fixing the side plate 21 from the longitudinal direction at two positions.

Next, the bracket 136 disposed at the upper part of the tank closing portion 134 of the cap 23 will be explained with reference to FIG. 11. FIG. 11A is an overall front view of the bracket 136, FIG. 11B is its top view and FIG. 11C is a right-hand side view. Incidentally, the bracket 136 shown in FIG. 11 represents a single body of the bracket 136 before it is disposed on the tank cap 23.

The bracket 136 is for coupling the condenser 1 with the radiator 2 for the electric components and has a coupling surface portion 136 a coupled with the tank closing portion 134 and a fitting surface portion 136 b to which the radiator 2 for the electric components is fitted. The coupling surface portion 136 a has a pin provisional fixing hole 136 c as a through-hole to which a later-appearing pin member 137 is caulked.

The coupling surface portion 136 a and the fitting surface portion 136 b have a positional relation such that they cross each other substantially orthogonally on the front surface side of the condenser 1. The bracket portion 136 is substantially L-shaped as viewed from the side of the evaporator 1 as shown in FIG. 11C.

In this embodiment, the tank cap 23 and the bracket 136 are coupled with each other in the provisional fixing state (sub-assembled state) as will be described later. Provisional fixing of the tank cap 23 and the bracket 136 will be explained with reference to FIGS. 12 and 13. FIG. 12A is an overall front view of the tank cap 23 and the bracket 136 in the provisional fixing state, FIG. 12B is its top view and FIG. 13 is a sectional view taken along a line B′-B′ of FIG. 12A.

Incidentally, dash line in FIG. 13 represents, for reference, the positional relationship between the evaporator 1 and the radiator 2 for the electric components coupled with each other through the bracket 136.

The tank cap 23 and the bracket 136 are provisionally fixed as the pin member 137 is caulked as shown in FIG. 13. More concretely, the pin member 137 is inserted into the pin provisional fixing hole portion 134 b of the tank cap 23 and into the pin provisional fixing hole 136 c of the bracket 136 and in this state, a load is applied from the outer peripheral side at the end in the vertical direction of the pin member 137 so that the pin member 137 undergoes plastic deformation and is provisionally fixed.

Because the load is applied to the pin member 137 from the direction indicated by arrows C′, D′, E′ and F′ in this embodiment, the pin member 137 can simultaneously caulk and provisionally fix the pin provisional fixing hole portion 134 b of the tank cap 23 and the pin provisional fixing hole 136 of the bracket 136.

Next, the tank caps 138 arranged at the lower end of the first refrigerant header tank 14 and the upper and lower ends of the second refrigerant header tank 15 will be explained with reference to FIG. 14. FIG. 14A is an overall front view of the tank cap 138 and FIG. 14B is its top view. Incidentally, the tank cap 138 shown in FIG. 14 represents the tank cap 138 in the single body state before it is fitted to the lower end of the first refrigerant header tank 14 and to the upper and lower ends of the second refrigerant header tank 15.

The tank cap 138 closes the lower end of the first refrigerant header tank 14 and the upper and lower ends of the second refrigerant header tank 15. However, the bracket for fitting is not coupled.

The tank cap 138 includes a tank closing portion 138 a and a cap extension portion 138 b. The tank closing portion 138 a has positioning flange portions 138 at three positions in the same way as the tank closing portion 134 of the tank cap 23 but does not have the pin provisional fixing hole portion.

The cap extension portion 138 b has entirely the same constitution as the cap extension portion 135 of the tank cap 23 and includes a positioning flange 138 d for positioning and provisional fixing and a pawl portion 139 for caulking and provisional fixing. Therefore, the tank cap 23 and the tank cap 138 are different from each other in only whether or not they have the pin provisional fixing hole portion. In other words, the tank cap 23 is formed by providing the pin provisional fixing hole portion 134 to the tank cap 138.

The condenser 1 has the constitution described above and all the constituent components of the condenser 1 are formed of an aluminum alloy and are integrally coupled by brazing.

Next, the production of the heat exchanger according to the invention will be explained. The evaporator 1 and the radiator 2 for the electric components are separately produced and are then coupled integrally with each other as described above. Therefore, the production process of the evaporator 1 will be first explained.

In the production process of the evaporator 1, the condenser 1 is assembled by inserting a large number of refrigerant tubes 11 into the slit holes formed in the first and second refrigerant header tanks 14 and 15 and sandwiching the fins 12 between the refrigerant tubes 11. The side plate 21 is arranged on the refrigerant tube 11 of the uppermost stage through the fins 12 and the side plate 21 is arranged below the refrigerant tube 11 of the lowermost stage through the fins 12.

In this state, a wire (jig) is wound at a predetermined tension from the outer peripheral side of the side plate 21 and is provisionally fixed to prevent deviation in the vertical direction.

The refrigerant inlet pipe 16 and the refrigerant outlet pipe 17 are provisionally fixed to the first refrigerant header tank 14 by caulking at the through-hole positions formed in advance in the first refrigerant header tank 14. The first separator 14 a is provisionally fixed at a predetermined position inside the first refrigerant header tank 14.

On the other hand, the plate 19 and the gas/liquid separator 18 are provisionally fixed by caulking to the second refrigerant header tank 15 in such a fashion as to mate with the through-hole positions disposed in advance in the second refrigerant header tank 15. The second separator 15 a is provisionally fixed at a predetermined position inside the second refrigerant header tank 15. Further, the bracket 22 for fitting the radiator 3 for the engine is provisionally fixed by caulking to the side plate 21 on the lower side.

In this state, all the components are held from both right and left sides by a dedicated jig lest they are deviated. Simultaneously with the production steps described above, the tank cap 23 and the bracket 136 are assembled into the sub-assembly by the pin member 137 as described already. The formation of this sub-assembly may be executed at any time before the tank cap 23 is provisionally fixed to the upper end of the first refrigerant header tank 14.

Next, the tank cap 23 is provisionally fixed to the upper end of the first refrigerant header tank 14 and the tank caps 138 are provisionally fixed to the lower end of the first refrigerant header tank 14 and the upper and lower ends of the second refrigerant header tank 15.

More concretely, the tank cap 23 is provisionally fixed to the upper end of the first refrigerant header tank 14 as shown in FIGS. 15 and 16. FIG. 15 is an enlarged view of a portion in proximity with the tank cap 23 (C portion in FIG. 1) and dash line represents the radiator 2 for the electric components that is shown for reference. FIG. 16 is a sectional view taken along a line H′-H′ in FIG. 15.

First, the upper end of the first refrigerant header tank 14 is clamped by the positioning flange 134 a of the tank cap 23 and the side plate 21 is clamped by the positioning flange 135 a. Further, as shown in FIG. 16, the pawl portion 135 b is caulked in such a manner as to extend below the side plate 21 along the outer edge shape of the side plate 21. The pawl portion 135 b achieves stronger provisional fixing than when clamping is done by the positioning flanges 134 a and 135 a alone.

As for the tank cap 138, too, the end portions of the header tanks 14 and 15 and the side plate 21 are clamped by the positioning flanges 138 c and 138 d in entirely the same way and the tank cap 138 is caulked and provisionally fixed to the side plate 21 by the pawl portion 139.

In this state, the entire constituent components are heated to about 600° C., by heating means, to melt the brazing material clad in advance to the surface of each constituent component. When cooling is done until the brazing material is again solidified, the constituent components are integrally brazed and the evaporator 1 is produced.

Incidentally, the brazing material is clad to a thickness of about 0.15 mm on the side of the tank closing portion 134 of the coupling surface portion 136 a of the bracket 136 and the brazing material is clad to a thickness of about 0.075 mm on the side of the coupling surface portion 136 a of the bracket 136 of the tank cap 23. In this way, the tank cap 23 and the bracket 136 can be satisfactorily brazed.

Next, in the production process of the radiator 2 for the electric components, the radiator 2 is assembled by inserting a large number of cooling water tubes 31 into the slit holes formed in the first and second cooling water header tanks 34 and 35 and sandwiching the fins 32 between the cooling water tubes 31. These members are provisionally fixed by a wire lest they are deviated in the vertical direction in the same way as the evaporator 1.

The refrigerant inlet pipe 36 is provisionally fixed to the first refrigerant header tank 34 by caulking at the through-hole positions formed in advance in the first cooling water header tank 34 and the cooling water outlet pipe 37 and the air vent valve 38 are provisionally fixed to the second cooling water header tank 35 by caulking at the through-hole positions formed in advance in the second cooling water header tank 35.

The bracket 40 for fitting the radiator 3 for the engine is provisionally fixed by caulking to the side plate 39 on the upper end side. In this state, the members are held by a dedicated jig, from both the right and the left sides, to prevent deviation.

Next, the tank caps for the cooling water header tanks 34 and 35 are provisionally fixed to the upper and lower ends of these cooling water header tanks 34 and 35 in the same way as the condenser 1. In this state, each constituent component is brazed and the radiator 2 for the electric components is produced.

Next, the condenser 1 and the radiator 2 for the electric components that are separately produced as described above are integrated by fastening the bolt 41 penetrating through the bracket portion 138 of the tank cap 23 to the screw hole formed in the first cooling water header tank 34 and further fastening the bolt 42 penetrating through the bracket 20 to the screw hole formed in the second cooling water header tank 35. In this way the heat exchanger according to this embodiment is produced.

In the heat exchanger according to the embodiment described above, the tank cap 23 to which the bracket 136 is provisionally fixed by the pin member 137 is provisionally fixed to the upper end of the fist refrigerant header tan 14 and is brazed simultaneously with the evaporator 1. Therefore, the bracket 136 can be provided on the tank cap 23 without inviting an increase in production cost of the evaporator 1.

The bracket 136 and the tank cap 23 are provisionally fixed (sub-assembled) by caulking the pin member 137. Therefore, provisional fixing can be made without making the shape of the bracket complicated and without inviting a drop in the strength, and an increase in the cost necessary for provisional fixing can be limited.

The tank cap 23 is obtained by forming the provisional fixing hole 134 b in the tank cap 138. Therefore, the mold used for producing the tank cap 23 and the mold used for producing the tank cap 138 can be used in common and the production cost can be further reduced. Moreover, the tank cap 23 and the tank cap 138 can be easily distinguished by the existence or absence of the pin provisional fixing hole.

Further, the bracket 136 is arranged on the tank cap 23 and the adjacent header tanks of the condenser 1 and the radiator 2 for the electric components are fastened with each other through the bracket 136. Therefore, the distance between the condenser 1 and the radiator 2 for the electric components can be reduced and the fastening strength can be secured.

Finally, other embodiments of the invention will be explained.

(1) In the foregoing embodiments, the examples of the heat exchanger formed by integrating a plurality of heat exchangers having the condenser 1 and the radiator 2 for the electric components coupled with each other has been explained. However, the combination of a plurality of heat exchangers is not limited thereto. For example, the heat exchanger may well be the one that integrates the condenser 1 with an oil cooler for cooling oil.

(2) The foregoing embodiments employs a sub-cool-type condenser for super-cooling the liquid-phase refrigerant for the condenser 1 but a condenser not having the super-cooling portion 13 b and the gas/liquid separator 18 may be used.

(3) In the foregoing embodiments, the tank cap 23 in which the bracket 24 is provisionally fixed to only the upper end of the first refrigerant header tank is coupled but the portion where the tank cap having the bracket provisionally fixed thereto is not limited to the upper end of the first refrigerant header tank.

When the length of the evaporator 1 in the transverse direction is equal to the length of the radiator 2 for the electric components in the transverse direction, for example, the tank caps having the bracket provisionally fixed thereto are coupled and the evaporator 1 and the radiator 2 for the electric components may be integrated by utilizing these two brackets.

Furthermore, the tank caps having brackets provisionally fixed thereto may be coupled to the lower ends of the first and second refrigerant header tanks 14 and 15. The condenser 1 and the radiator 3 for the engine may be coupled by using these two brackets. They may also be used as the brackets for directly fixing to the vehicle.

(4) In the foregoing embodiments, the constituent components such as the refrigerant inlet pipe 16 and the refrigerant outlet pipe 17 are first fixed provisionally and are then integrally brazed but the constituent components are not limited to those which are used in the foregoing embodiments. Those constituent components which become necessary depending on the kind and application of the heat exchanger and which can be brazed may be provisionally fixed by caulking and may be then integrally brazed.

(5) The foregoing embodiments represent the example of the application of the present invention to the heat exchanger for the vehicle but the invention can be applied to heat exchangers in general without being limited to the vehicle heat exchangers as long as they are in conformity with the gist of the invention.

While the invention has been described by reference to specific embodiments chosen for purposes of illustration, it should be apparent that numerous modifications could be made thereto, by those skilled in the art, without departing from the basic concept and scope of the invention. 

1. A heat exchanger comprising: a core portion (13) having a plurality of tubes (11) through which a fluid flows; side plates (21) arranged on both end sides of said core portion (13) and reinforcing said core portion (13); a pair of header tanks (14, 15) arranged on both end sides of said tubes (11) in a longitudinal direction and communicating with said tubes (11); and tank caps (23, 28) closing the ends of said header tank (14) in the longitudinal direction; wherein at least one of said tank caps (23, 28) is a tank cap (23) with a bracket having a bracket (23) provided thereon; said tank cap (23) with a bracket has provisional fixing means (21) to said side plates (21); and said tank cap (23) with a bracket is coupled with said header tank (14) in a state where it is provisionally fixed to said side plates (21) by said provisional fixing means (25 b).
 2. A heat exchanger comprising a first heat exchanger (1) and a second heat exchanger (2), wherein said first heat exchanger (1) includes: a first core portion (13) having a plurality of first tubes (11) through which a first fluid flows; side plates (21) arranged on both end sides of said first core portion (13) and reinforcing said first core portion (13); a pair of first header tanks (14, 15) arranged on both end sides of said first tubes (11) in a longitudinal direction and communicating with said first tubes (11); and tank caps (23, 28) closing the ends of said first header tank (14) in the longitudinal direction; wherein at least one of said tank caps (23, 28) is a tank cap (23) with a bracket having a bracket (26) provided thereon; and said second heat exchanger (2) includes: a second core portion (33) having a plurality of second tubes (31) through which a second fluid flows; and a pair of second header tanks (34, 35) arranged on both end sides of said second tubes (31) in a longitudinal direction and communicating with said second tubes (31); said tank cap (23) with a bracket having provisional fixing means (25 b) to said side plates (21); said bracket (23) with a bracket being coupled with said first header tank (14) in a state where it is provisionally fixed to said side plates (21); said first heat exchanger (1) and said second heat exchanger (2) being coupled in parallel with each other through said bracket (26) with respect to a flow direction of a third fluid that executes heat exchange with said first fluid and said second fluid.
 3. A heat exchanger according to claim 1, wherein said provisional fixing means is a pawl portion (25 b) caulked to an outer edge portion of said side plate (21) when it is bent.
 4. A heat exchanger according to claim 2, wherein said provisional fixing means is a pawl portion (25 b) caulked to an outer edge portion of said side plate (21) when it is bent, and said pawl portion (25 b) is caulked to a portion in proximity with a coupling portion between said side plate (21) and said first header tank (14).
 5. A method for producing a first heat exchanger (1) as defined in claim 2, comprising: the first step for provisionally fixing said tank cap (23) with a bracket to said side plate (21) by said provisional fixing means (25 b); and the second step for coupling said tank cap (23) with a bracket and said first header tank (14) after said first step.
 6. A heat exchanger comprising: a core portion (13) having a plurality of tubes (11) through which a fluid flows; a pair of header tanks (14, 15) arranged on both end sides of said tubes (11) in a longitudinal direction and communicating with said tubes (11); and tank caps (23, 138) closing the ends of said header tanks (14, 15) in the longitudinal direction; a bracket (136) coupled with at least one of said tank caps (23, 138); and a pin member (137) for provisionally fixing said tank cap (23) and said bracket (136); wherein said pin member (137) is caulked and provisionally fixed to provisional fixing hole portion (134 b) formed in said tank cap (23) and a provisional fixing hole portion (136 c) formed in said bracket (136); and said tank cap (23) and said bracket (136) is coupled in a state where they are caulked and provisionally fixed.
 7. A heat exchanger comprising a first heat exchanger (1) and a second heat exchanger (2), wherein said first heat exchanger (1) includes: a first core portion (13) having a plurality of first tubes (11) through which a first fluid flows; a pair of first header tanks (14, 15) arranged on both end sides of said first tubes (11) in a longitudinal direction and communicating with said first tubes (11); tank caps (23,138) closing the ends of said first header tanks (14, 15) in the longitudinal direction; a bracket (136) coupled with at least one of said tank caps (23, 138); and a pin member (137) for provisionally fixing said tank cap (23) and said bracket (136); and wherein said second heat exchanger (2) includes: a second core portion (33) having a plurality of second tubes (31) through which a second fluid flows; and a pair of second header tanks (34, 35) arranged on both end sides of said second tubes (31) in a longitudinal direction and communicating with said second tubes (31); said pin member (137) being caulked and provisionally fixed to a pin provisional fixing hole portion (34 b) formed in said tank cap (23) and to a pin provisional fixing hole portion (136 c) formed in said bracket (136); said tank cap (23) and said bracket (23) being coupled with each other in a state where they are caulked and provisionally fixed; said first heat exchanger (1) and said second heat exchanger (2) being coupled in parallel with each other through said bracket (136) with respect to a flow direction of a third fluid that executes heat exchange with said first fluid and said second fluid.
 8. A heat exchanger according to claim 6, wherein said tank caps (23, 138) include a tank cap (138) to which said bracket (136) is not coupled.
 9. A production method for a heat exchanger according to claim 6, which further comprises: the first step for caulking and provisionally fixing said pin member (137) to a pin provisional fixing hole portion (134 b) formed in said tank cap (23) and to a pin provisional fixing hole portion (136 c) formed in said bracket (136); and the second step for coupling said tank cap (23) and said bracket (136) in a state where they are caulked and provisionally fixed. 